Measurement of xenon-doped liquid argon scintillation yield

Noble liquid detectors are widely used in the field of dark matter direct detection. Doping liquid argon with small amounts of xenon has the effect of shifting the wavelength of the scintillation light from 128nm to 174nm. This allows us to construct argon-based dark matter detectors without additional wavelength shifters. Additionally, xenon-doped argon could lower the detection threshold of low-mass WIMP detectors. To pursue low-mass WIMP searches with xenon-doped argon detectors, we studied the scintillation yield of xenon-doped liquid argon. We deployed a single-phase detector instrumented with VUV-sensitive silicon photomultiplier modules. Half of these modules feature fused silica windows that act as filters to isolate scintillation contributions from argon and xenon dimers. This configuration allows for a distinct measurement of scintillation yield from argon and xenon dimers. This measurement is instrumental in defining the design requirements of future xenon-doped argon detectors for low-mass WIMP searches.